U.S. Pat. No. 6,392,611 describes an array fed multiple beam antenna system and method for use on an orbiting spacecraft carrying a communication system. The antenna system includes a reflector and a relatively small array feed compared to the reflector. The array feed has feeds comprising radiators that illuminate the reflector and that are disposed in a focal plane of the reflector. A power division network excites the radiators of the feeds. The antenna system is capable of very wide scan angle operation and may be used to provide multiple spot beam coverage over the surface of the Earth viewed from a synchronous orbit spacecraft. Phase aberration normally associated with scanning is corrected by adjusting excitation coefficients of each array feed.
However, the known systems are not accurate enough such that the optimum performance of the radiated beam is not achieved.